Congrats on the top 8. Did you run deluge specifically because of Eldrazi? It didn't appear to come up in your games. I've been trying firestorm instead and would be interested to hear your thoughts on how often you had deluge but your own creatures on board you didn't want to kill.

I put in Toxic Deluge against White Eldrazi primarily, even though obviously there was no need for it in this tournament (but that is something I wouldn't know thanks to you three).

So far what I can say about playing with the card is the fact that the card performed the best against Gush decks (mirrors mostly). Whenever I couldn't deal with more tokens on the other side of the table Toxic Deluge while even killing my own creatures was very good. As far as I remember I never (or very rarely) played it when it was only my opponent having creatures in play. Sometimes it ended up in a race to find another token generator (when I was desperate and hoped Deluge would give me time to turn the game in my favor) but I usually landed Dack Fayden or Jace, the Mind Sculptor after clearing the board and that always resulted in a win.

Against the deck I originally wanted to test the card it either did not show up (difficult to get to it since Thorn effects make everything difficult to cast) or I couldn't play it due to low life total or too many Thorn effects in play (while playing against Boin in Daily he had 3 Thorn effects on a stick and 2 artifact ones!), single Deluge would have solved my problem but I couldn't get that amount of mana in time, but I wouldn't be able to play Firestorm either in this case. In paper (played more games in paper) I often stabilized my board position while being down to 1 or 2 life and could not even deal with Thalia (I usually still needed one life to either fetch or play Force of Will).

Whenever I managed to play Young Pyromancer against Eldrazi or Shops I never needed a global removal so in those cases Toxic Deluge was a dead card in my hand. After some games against different players (not really good pilots usually) I realized that this matchup is actually not that bad as I thought it would be at first. Unfortunately I did not find a better card than Snuff Out that would help me with it. We talked about this a bit with other local Vintage players and one suggested playing Firestorm. I wasn't really sold on that idea but after realizing that all I need is to pay 1 mana and discard 1 or 2 cards I started to actually consider it more seriously. Often in these situations I have disruption that I cannot play, Gush or Cruise/Dig Through Time. I had Lightning Bolt there instead before because sometimes there are black creatures I need to kill. But when I played the bolt I also ran Snapcaste Mage so I could flashback it. Jace, Vryn's Prodigy seems superior though in most cases so I decided to cut both cards and see what Deluge can do. The problem with bolt is also the fact that it costs 1 mana and I need something that does not get missteped.

At Eternal Weekend though I'd like to play other/additional removal because I would expect more creatures, namely Leovold, Dark Confidant, Kambal and possibly Sanctum Prelate/new recruiter (I'm not really sure if this card is good...I mean it is but WW seems too much for my like). Many of the creatures are black so Snuff Out won't really do and I would really love some kind of sweeper but what I need is that it can possibly (under certain conditions deal with 3-4 thoughness creatures, 3 being a must and 4 can sometimes come handy). Baleful Strix is not good enough for that since those creatures won't attack me. But I like the Strixen and would like to keep them in my list. Without these cards I wouldn't be able to have a game against many strange decks I was encountering (not really strange decks but rather against decks I did not expect the Strix would be any good) Dredge, UW Moat control decks etc.

I also feared cards like Spell Queller and some other esper 2/1s or BUG Fish (I kinda of forgot that CN2 is not available on modo) so that is why I put in my deck for the P9C. It seems to me that you guys here actually like to brew and come up with something for the new meta and this was the other direction I expected (the first one being more pro-Shops). Toxic Deluge wasn't a good choice though and I wouldn't recommend playing it.

(but I guess you know more about all this than me^_~, sorry for the long)

I put in Toxic Deluge against White Eldrazi primarily, even though obviously there was no need for it in this tournament (but that is something I wouldn't know thanks to you three).

So far what I can say about playing with the card is the fact that the card performed the best against Gush decks (mirrors mostly). Whenever I couldn't deal with more tokens on the other side of the table Toxic Deluge while even killing my own creatures was very good. As far as I remember I never (or very rarely) played it when it was only my opponent having creatures in play. Sometimes it ended up in a race to find another token generator (when I was desperate and hoped Deluge would give me time to turn the game in my favor) but I usually landed Dack Fayden or Jace, the Mind Sculptor after clearing the board and that always resulted in a win.

Against the deck I originally wanted to test the card it either did not show up (difficult to get to it since Thorn effects make everything difficult to cast) or I couldn't play it due to low life total or too many Thorn effects in play (while playing against Boin in Daily he had 3 Thorn effects on a stick and 2 artifact ones!), single Deluge would have solved my problem but I couldn't get that amount of mana in time, but I wouldn't be able to play Firestorm either in this case. In paper (played more games in paper) I often stabilized my board position while being down to 1 or 2 life and could not even deal with Thalia (I usually still needed one life to either fetch or play Force of Will).

Whenever I managed to play Young Pyromancer against Eldrazi or Shops I never needed a global removal so in those cases Toxic Deluge was a dead card in my hand. After some games against different players (not really good pilots usually) I realized that this matchup is actually not that bad as I thought it would be at first. Unfortunately I did not find a better card than Snuff Out that would help me with it. We talked about this a bit with other local Vintage players and one suggested playing Firestorm. I wasn't really sold on that idea but after realizing that all I need is to pay 1 mana and discard 1 or 2 cards I started to actually consider it more seriously. Often in these situations I have disruption that I cannot play, Gush or Cruise/Dig Through Time. I had Lightning Bolt there instead before because sometimes there are black creatures I need to kill. But when I played the bolt I also ran Snapcaste Mage so I could flashback it. Jace, Vryn's Prodigy seems superior though in most cases so I decided to cut both cards and see what Deluge can do. The problem with bolt is also the fact that it costs 1 mana and I need something that does not get missteped.

At Eternal Weekend though I'd like to play other/additional removal because I would expect more creatures, namely Leovold, Dark Confidant, Kambal and possibly Sanctum Prelate/new recruiter (I'm not really sure if this card is good...I mean it is but WW seems too much for my like). Many of the creatures are black so Snuff Out won't really do and I would really love some kind of sweeper but what I need is that it can possibly (under certain conditions deal with 3-4 thoughness creatures, 3 being a must and 4 can sometimes come handy). Baleful Strix is not good enough for that since those creatures won't attack me. But I like the Strixen and would like to keep them in my list. Without these cards I wouldn't be able to have a game against many strange decks I was encountering (not really strange decks but rather against decks I did not expect the Strix would be any good) Dredge, UW Moat control decks etc.

I also feared cards like Spell Queller and some other esper 2/1s or BUG Fish (I kinda of forgot that CN2 is not available on modo) so that is why I put in my deck for the P9C. It seems to me that you guys here actually like to brew and come up with something for the new meta and this was the other direction I expected (the first one being more pro-Shops). Toxic Deluge wasn't a good choice though and I wouldn't recommend playing it.

(but I guess you know more about all this than me^_~, sorry for the long)

I see you are already on Murderous Cut in the sideboard, but I would take a look at dismember over snuff out. It hits any creature including all the relevant eldrazi, is great against mentor, is 1 less life loss rolled off a bob...relevant for me :)...and has the same life loss cost as snuff out but with way more flexibility.

That one mana difference between Snuff Out and Dismember can be really important if you're trying to kill a creature through spheres, or respond to a TKS trigger while tapped out. The 4-life cost definitely means diminishing returns on multiples though, and it's worse with JVP/Snapcaster, so I think there's a fair argument for a mix of Snuff Outs and other removal (which is what you see in most of these decks). I wouldn't want to be on Dismembers over Snuff Outs in the meta right now ... but that could always change.

as Andy said I don't run Dismember because it simply costs too much, it costs both life and mana. The difference of 1 mana is huge and 'flashblacking' it is a pain and I don't care about the CMC unless it costs 1. Sometimes being able to Dismember for 3 mana instead of 4 would be nice but I don't get often in that situation (even I do). Even though I fetch for Underground Sea more often I don't often have double black either.
So I did not even consider running it. Playing Young Pyromancer/JVP and then playing Snuff Out while tapped out is important.